The present disclosure relates to data backups, and more specifically, to file-level and block-level backups.
When backing up data, two different methods are typically used. One method is file-level backups which performs the backup task by copy files and directories to a separate folder (or directory) structure. The granularity of this type of backup allows a small subset of folders or files to be designated for backup. Also this method allows flexible backup policies for different data types on the same volume. For example, the backup policies for documents, photographs, videos, etc. can all be different even though they reside on the same volume. This method also has detriments such as being time consuming for large amounts of data and copying a whole file during a backup operation even though only a small portion of the file may have changed.
Another backup method is at the block-level. A block-level backup is defined at blocks which are generally a group of disk sectors. This type of backup is at a lower level than files and folders and is performed below the file system level. Generally, block-level backups are used to accomplish disk-to-disk copies or volume-to-volume copies. Block-level backups allow backing up or restoring an entire volume or disk as block units. Block-level backups utilize more sophisticated software than file-level backups and typically require kernel-level drivers such as a snapshot driver and a change tracking driver to perform their tasks.